We have studied before the freeze-out of hadrons in general driven by reaction \(\pi ^0\Leftrightarrow \gamma +\gamma \)  [1]}, and we compare with these results in this work. We considered the connection of the QGP phase with later stages of the Universe evolution [2]}, and explored in more detail the neutrino evolution, which relates to the question of the cosmic neutrino abundance [3]}, and free-streaming neutrino momentum distribution [4]}. This work and its follow-up findings [5]} could influence the speed of Universe expansion, a topic generating a lot of interest today [6]}, [7]}.
